3-hydroxydiphenyleneoxide-2-carboxylic acid



Patented Aug. 11, 1936 v UNITED STATES PATENT OFFICE 3-HYDROXYDIPHENYLENEOXIDE-2- CARBOXYLIC ACID Friedrich Muth, Leverkusen-I. G.-Werk, Germany, assignor to General Aniline Works, Inc., New York, N. Y., a corporation of Delaware No Drawing. Application September 25, 1933, Serial No. 690,951. In Germany October 5, 1932 1 Claim. (Cl. 260-54) The present invention relates to new ortho forced in and the autoclave is heated during 8-10 hydroxycarboxylic acids of the diphenylene series, hours at 210-220 C. After cooling, the carbon more particularly it relates to the compound of dioxide is removed, the content of the autoclave the formula: is dissolved in hot water and filtered. On cool-'- ing, from the filtrate crystallizes the potassium 5 4 3 0H salt of the 34-hydroxydiphenyleneoxide-2-car- I boxylic acid in needles. The salt is filtered with CO0H suction, again dissolved in hot water, and the free acid is precipitated by the addition of hydrochloric In accordance with the present invention the acid, h new d having th following 0 compound of the above identified formula is prefor ula; pared by starting with the 3-hydroxy-diphenyleneoxide and treating it according to the synthesis OH of Kolbe in the presence of an alkali, or in form of an alkali metal salt thereof, with carbon- 0/ GOOH 15 dioxide under su eratmos heric ressure and at elevated tempemgure. p p is obtained after recrystallization from pyridine Fr th hemical behaviour of m new a in pale yellow needles of the melting point 293 C. a appears that the carbsxylic acid On the addition of ferric chloride to its alcoholic oup stands in ortho-position with respect to the m a reddlsh-blue colomilon enters- 20 hydroxy group, and from my present knowledge I Ewample D as by welght of 3-hydroxyassume that it enters the 2-position; I wish it to diphenylenePxlde are mfilmately mlxed Wlth 100 be understood, however, that, in case the carparts y f" of dry Potassium carbonate and boxylic acid group should enter the other posithe mlxtm'e ifltrodueed an f' tion ortho with respect to the hydroxy group, carPon dloxldf is pressed the tempela" that is the ,imosmon, this compound falls within ture is raised to 150 C. in the course of 5-6 hours the Scope of my invention and kept at this temperature for about 10-12 The starting 3-hydroxydiphenyleneoxide is obhours; After eeohngi the carbon dloxld-e f tainable for example, by treating the correspondfis removed the content e aumelave 15 mg 3 cmoro compounds with caustic aqueous dissolved in hot water, the solution is filtered, and alkali at elevated temperature and under sump the filtrate is evaporated until crystallization of atmospheric pressure, or by diazotizing the correthepotasslum salt further Workmg sponding 3-amino-compound and boiling the diup 15 f e as e e 1n The azo compound obtained therefrom in the presence earbexyhe acid obtamed 1S identleal Wlth that of phosphoric acid. described in Example 1.

My new ortho-hydroxycarboxylic acid is a I elalm: water-insoluble pale yellow-colored substance, 3 hydrXyd1 pheny1enex1de'2'earboxync acid soluble in aqueous alkalies and organic solvents of the formulaand is a valuable intermediate product in the 40 manufacture of dyestuffs. OH 40 The invention is illustrated by the following examples, without being limited thereto: 0 11 Example 1.18.4 parts by weight of 3-hydroxydiphenyleneoxide are transformed into the pobemg a p le yellow crystall ne substance of the tassium salt according to methods known per se. melting Pemt 293 and belng a Valuable ter- 45 The potassium Salt is ground with parts by mediate product in the manufacture of dyestuffs.

weight of potassium carbonate, the mixture is introduced into an autoclave, carbondioxide is FRIEDRICH MUTH- 

